Catalyst and process for preparing acrolein and/or acrylic acid by dehydration reaction of glycerin

Abstract

A catalyst composition comprising at least an heteropolyacid deposited on a porous titania carrier. A catalyst composition comprising at least an heteropolyacid in which protons in the heteropolyacid may be partially exchanged by at least one cation selected from elements belonging to Group 1 to Group 16 of the Periodic Table of Elements that have been deposited on a porous titania carrier. A method for preparing the catalyst composition, comprising impregnating a titania carrier with a solution of at least one metal selected from elements belonging to the Group 1 to Group 16 of the Periodic Table of Elements or onium, drying and firing the resulting solid mixture, secondly impregnating the resulting solid mixture with a solution of heteropolyacid, drying, and firing the resulting solid mixture. A process for preparing acrolein and acrylic acid by dehydration of glycerin, carried out in the presence of the catalyst.

The invention claimed is: 
     
       1. A process for preparing acrolein by dehydration of glycerin, carried out in the presence of a catalyst, wherein the catalyst composition comprises at least an heteropolyacid in which protons in the hetropolyacid may be partially exchanged by at least one cation of elements belonging to Group 1 to Group 16 of the Periodic Table of Elements that have been deposited on a porous titania carrier. 
     
     
       2. The process of  claim 1 , in which said porous titania carrier is covered at least partially by a compound represented by the formula (1):
   H a A b [X 1 Y c Z d O e   ].n H 2 O  (I)
 
 
       in which
 H is hydrogen, 
 A is more than one cation of an element belonging to Group 1 to Group 16 of the Periodic Table of Elements except hydrogen, 
 X is P or Si, 
 Y is more than one of W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Tl, Sn or Pb, 
 Z is more than one of W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co. Ni, Cu, Zn, Ga, In, Tl, Sn or Pb, 
 a, b, c, d and n are:
 0≦a<9 
 0≦b≦9, 
 0<c≦12 and 
 0≦d<12 
 n≧0 
 
 and e is a number determined by the oxidation of the elements. 
 
     
     
       3. The process of  claim 2 , in which said compound contains at least one of W, Mo or V. 
     
     
       4. The process of  claim 2 , wherein 0<b≦9. 
     
     
       5. The process of  claim 1 , in which said titania carrier comprises rutile or anatase or amorphous titanium oxide. 
     
     
       6. The process of  claim 1 , in which said titania carrier comprises at least 80% anatase. 
     
     
       7. The process of  claim 1 , in which said cation is at least one alkali metal cation. 
     
     
       8. The process of  claim 1 , in which said alkali metal is cesium. 
     
     
       9. The process of  claim 1 , in which dehydration of glycerin is effected in the presence of molecular oxygen. 
     
     
       10. The process of  claim 1  in which dehydration of glycerin is effected in the presence of a gas containing propylene. 
     
     
       11. The process of  claim 1  carried out in a reactor of the plate heat exchanger type or in a fixed bed reactor or in a fluidized bed type reactor or in a circulating fluidized bed or in a moving bed. 
     
     
       12. The process of  claim 1 , in which the resulting acrolein is further oxidized to produce acrylic acid. 
     
     
       13. The process of  claim 12 , having an intermediate step of partial condensation of water and heavy by-products issuing from the dehydration step. 
     
     
       14. The process of  claim 1 , followed by second step of ammoxidation of acrolein to acrylonitrile. 
     
     
       15. A process for preparing acrolein by dehydration of glycerin, carried out in the presence of a catalyst, wherein the catalyst is prepared according to a method for preparing a catalyst composition comprising impregnating a titania carrier with a solution of at least one metal of Group 1 to Group 16 of the Periodic Table of Elements or onium, drying and firing the resulting solid mixture, secondly impregnating the resulting solid mixture with a solution of heteropolyacid, drying, and firing the resulting solid mixture. 
     
     
       16. The process of  claim 15 , in which one impregnation is made with a phosphotungstic acid or phosphotungstate solution. 
     
     
       17. The process of  claim 15 , in which one impregnation is made with a silicotungstic acid or silicotungstate solution. 
     
     
       18. The process of  claim 15 , in which one impregnation is made with a cesium salt solution. 
     
     
       19. A process for preparing acrolein by dehydration of glycerin, carried out in the presence of a catalyst, wherein the catalyst is prepared according to a method for preparing a catalyst composition comprising impregnating a titania carrier with a solution of heteropolyacid, drying and firing the resulting solid mixture, optionally secondly impregnating the resulting impregnated carrier with a solution of at least one metal of Group 1 to Group 16 of the Periodic Table of Elements or onium, drying, and firing the resulting solid mixture. 
     
     
       20. The process of  claim 19 , in which one impregnation is made with a phosphotungstic acid or phosphotungstate solution. 
     
     
       21. The process of  claim 19 , in which one impregnation is made with a silicotungstic acid or silicotungstate solution. 
     
     
       22. The process of  claim 19 , in which one impregnation is made with a cesium salt solution. 
     
     
       23. A process for preparing acrolein by dehydration of glycerin, carried out in the presence of a catalyst, wherein the catalyst is prepared according to a method for preparing a catalyst composition prepared by more than one cycle of impregnation and firing, in which each impregnation is effected with a solution of an element of Group 1 to Group 16 of the Periodic Table of Elements or onium or with a solution containing more than one of P, Si, W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Tl, Sn, or Pb, and in which at least one impregnation is made with an acid precursor. 
     
     
       24. The process of  claim 23 , in which one impregnation is made with a phosphotungstic acid or phosphotungstate solution. 
     
     
       25. The process of  claim 23 , in which one impregnation is made with a silicotungstic acid or silicotungstate solution. 
     
     
       26. The process of  claim 23 , in which one impregnation is made with a cesium salt solution.